Finding my professor and registering the data on a tablet


I have got a project with a group of mine to find our professor when he is inside our school. I have thought of using sensors everywhere and then make them communicate with an arduino card whom is connected to a display (tablet?) which registers everytime my professor bypasses a sensor, example: 21.30 ---- Proffesor X is at his office --- 08.01.2017. The plan is to use a tablet where we monitor it outside his office and the user can just look at the tablet and see the last 10 or more places he bypassed.

What my question is, i dont know how to make all the sensors communicate with eachother, and is it possible to make the arduino card communicate with my proffesors phone? What i am thinking is whenever he bypasses a sensor --> his phone will direct a signal to the arduino card which then will register everything on a database and show it on the tablet.

Anyone have some good tips for how to start?

PS: sorry for my poor english, not my first language :)

The sensors don't need to communicate with each other. They only need to communicate to the main board.

If the prof has bluetooth enabled on his phone you could use some bluetooth modules and if they pair then they are close to his phone.